INTRODUCTION: Social experience during adolescence plays a critical role in shaping adult behaviour. Evidence from both human and rodent studies indicates that social isolation during this period negatively affects emotional regulation and cognitive function. However, it remains unclear whether these impairments reflect permanent alterations or rather may be reversed by later social experience.

AIM(S): This study aimed to assess the effects of social isolation during adolescence, followed by resocialization, on adult social behaviour, anxiety-related responses, and learning.

METHOD(S): Female C57BL/6J mice were isolated for 2 weeks from postnatal days 21 to 35 and subsequently resocialized with same-sex, age-matched peers. Behavioural assessments were conducted on two separate cohorts after 2 or 7 weeks in social housing, using a test battery that evaluated social, emotional, and cognitive domains.

RESULTS: Adolescent isolation had no statistically significant effect on social memory, social rank within the home cage hierarchy, anxiety-like behaviour, or cognitive performance, although a trend toward reduced time spent in the centre of the open field was observed in the younger cohort.

CONCLUSIONS: These findings indicate a mild and potentially transient increase in anxiety-like behaviour, without evidence of broader behavioural deficits. Overall, the data are consistent with the notion that subsequent social experience may buffer the adverse effects of adolescent social isolation. Further studies including both male and female mice are needed to determine the long-term consequences and to better understand potential adaptive responses to adolescent social deprivation.

FINANCIAL SUPPORT: This study was supported by the European Union under the Horizon Europe Framework Programme. Grant Agreement number: E4H/III/4/SI-ADO-AGING/2026.